diff --git a/src/SQLSpelunker.Console/Program.cs b/src/SQLSpelunker.Console/Program.cs
index 32ddb50..88f0f6b 100644
--- a/src/SQLSpelunker.Console/Program.cs
+++ b/src/SQLSpelunker.Console/Program.cs
@@ -8,21 +8,59 @@ public class Program
     {
         static void Main(string[] args)
         {
-            var connectionString = "server=localhost;initial catalog=tsqlscheduler;integrated security=sspi";
-            var sqlScript = "exec scheduler.UpsertJobsForAllTasks";
+            var connectionString = string.Empty;
+            var sqlScript = string.Empty;
 
-            if(args.Length > 0)
+            if(args.Length == 2)
             {
                 connectionString = args[0];
                 sqlScript = args[1];
             }
+            else
+            {
+                WriteError("Invalid arguments");
+                WriteError("dotnet run <connection string> <sql script>");
+                return;
+            }
 
-            var builder = new SqlConnectionStringBuilder(connectionString);
+            SqlConnectionStringBuilder builder = null;
+            try
+            {
+                builder = new SqlConnectionStringBuilder(connectionString);
+            }
+            catch (ArgumentException ae)
+            {
+                WriteError($"Connection string is not valid: {ae.Message}");
+                return;
+            }
             var database = builder.InitialCatalog;
 
-            var sw = new ScriptWalker(new SQLDatabaseDefinitionService(connectionString));
+            if(string.IsNullOrWhiteSpace(database))
+            {
+                System.Console.WriteLine("Connection string does not specify database, defaulting to master");
+                database = "master";
+            }
+
+            // Establish connection
+            ScriptWalker sw = null;
+            try
+            {
+                sw = new ScriptWalker(new SQLDatabaseDefinitionService(connectionString));
+            }
+            catch (SqlException sx)
+            {
+                WriteError($"Unable to connect to database: {sx.Message}");
+                return;
+            }
             var callChain = sw.GetCalledProcedures(sqlScript, database);
             System.Console.WriteLine(callChain.GetCallHierarchy());
         }
+
+        private static void WriteError(string error)
+        {
+            var originalColour = System.Console.ForegroundColor;
+            System.Console.Error.WriteLine(error);
+            System.Console.ForegroundColor = originalColour;
+        }
     }
 }
diff --git a/src/SQLSpelunker.Core/Definitions/SQLDatabaseDefinitionService.cs b/src/SQLSpelunker.Core/Definitions/SQLDatabaseDefinitionService.cs
index cb3a40f..6099c38 100644
--- a/src/SQLSpelunker.Core/Definitions/SQLDatabaseDefinitionService.cs
+++ b/src/SQLSpelunker.Core/Definitions/SQLDatabaseDefinitionService.cs
@@ -19,6 +19,12 @@ public SQLDatabaseDefinitionService(string connectionString)
 
             _connectionString = connectionString;
             _definitions = new Dictionary<StoredProcedure, string>();
+
+            // Test connection during construction
+            using(var conn = new SqlConnection(connectionString))
+            {
+                conn.Open();
+            }
         }
 
         public string GetStoredProcedureDefinition(StoredProcedure storedProcedure)
diff --git a/src/SQLSpelunker.Core/SQLSpelunker.Core.csproj b/src/SQLSpelunker.Core/SQLSpelunker.Core.csproj
index 8af5947..4bad15f 100644
--- a/src/SQLSpelunker.Core/SQLSpelunker.Core.csproj
+++ b/src/SQLSpelunker.Core/SQLSpelunker.Core.csproj
@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
+    <NoWarn>NU1701</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>
@@ -9,4 +10,5 @@
     <PackageReference Include="System.Data.SqlClient" Version="4.4.2" />
   </ItemGroup>
 
+  
 </Project>